On Fri, Jan 8, 2021 at 12:16 AM Michael Walle <michael@xxxxxxxx> wrote: > > Am 2021-01-08 02:24, schrieb Saravana Kannan: > > The device link device's name was of the form: > > <supplier-dev-name>--<consumer-dev-name> > > > > This can cause name collision as reported here [1] as device names are > > not globally unique. Since device names have to be unique within the > > bus/class, add the bus/class name as a prefix to the device names used > > to > > construct the device link device name. > > > > So the devuce link device's name will be of the form: > > <supplier-bus-name>:<supplier-dev-name>--<consumer-bus-name>:<consumer-dev-name> > > > > [1] - > > https://lore.kernel.org/lkml/20201229033440.32142-1-michael@xxxxxxxx/ > > > > Cc: stable@xxxxxxxxxxxxxxx > > Fixes: 287905e68dd2 ("driver core: Expose device link details in > > sysfs") > > Reported-by: Michael Walle <michael@xxxxxxxx> > > Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx> > > --- > [..] > > The changes are missing for the error path and > devlink_remove_symlinks(), > right? Removing symlinks doesn't need the name. Just needs the "handle". So we are good there. > > diff --git a/drivers/base/core.c b/drivers/base/core.c > index 4140a69dfe18..385e16d92874 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -485,7 +485,7 @@ static int devlink_add_symlinks(struct device *dev, > goto out; > > err_sup_dev: > - snprintf(buf, len, "consumer:%s", dev_name(con)); > + snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), > dev_name(con)); > sysfs_remove_link(&sup->kobj, buf); > err_con_dev: > sysfs_remove_link(&link->link_dev.kobj, "consumer"); > @@ -508,7 +508,9 @@ static void devlink_remove_symlinks(struct device > *dev, > sysfs_remove_link(&link->link_dev.kobj, "consumer"); > sysfs_remove_link(&link->link_dev.kobj, "supplier"); > > - len = max(strlen(dev_name(sup)), strlen(dev_name(con))); > + len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)), > + strlen(dev_bus_name(con)) + strlen(dev_name(con))); > + len += strlen(":"); > len += strlen("supplier:") + 1; > buf = kzalloc(len, GFP_KERNEL); > if (!buf) { > @@ -516,9 +518,9 @@ static void devlink_remove_symlinks(struct device > *dev, > return; > } > > - snprintf(buf, len, "supplier:%s", dev_name(sup)); > + snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), > dev_name(sup)); > sysfs_remove_link(&con->kobj, buf); > - snprintf(buf, len, "consumer:%s", dev_name(con)); > + snprintf(buf, len, "consumer:%s:%s", dev_bus_name(sup), > dev_name(con)); > sysfs_remove_link(&sup->kobj, buf); > kfree(buf); > } > > With these changes: > > Tested-by: Michael Walle <michael@xxxxxxxx> Greg, I think it's good to pick up this version if you don't see any issues. > > This at least make the warning go away. Phew! > BUT, there is somesthing strange or at least I don't get it: > > # find /sys/bus/pci/devices/0000:00:00.0/ -name "consumer\:*" > # find /sys/bus/pci/devices/0000:00:00.1/ -name "consumer\:*" > /sys/bus/pci/devices/0000:00:00.1/consumer:mdio_bus:0000:00:00.1:04 > /sys/bus/pci/devices/0000:00:00.1/consumer:mdio_bus:0000:00:00.1 > > enetc0 (0000:00:00.0) has no consumers while enetc1 (0000:00:00.1) > has ones. Although both have PHYs connected. Here are the > corresonding device tree entries: > > enetc0: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/freescale/fsl-ls1028a-kontron-sl28.dts?h=v5.11-rc2#n81 > > enetc1: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/freescale/fsl-ls1028a-kontron-sl28-var4.dts?h=v5.11-rc2#n21 > > Why is there a link between enetc1 and its PHY (and MDIO bus) > but not for enetc0? So a lot of subtle things could be going on here that make it look like it's not working correctly but it's actually working fine. Since fw_devlink=permissive is the default mode, all links that are created are SYNC_STATE_ONLY links. These links are deleted after their consumers probe. So if you really want to see all the "real" links persist, try booting with fw_devlink=on. You might have boot issues though -- I'm working on that separately [1]. Also, SYNC_STATE_ONLY links can be created between the parent of a consumer and the supplier (I won't get into the why here) depending on some ordering -- so that might be causing some spurious looking links, but they aren't. Another way to do what you are trying to do is to enable the logs in device_link_add() and look at them to see if all the links are created as you'd expect. > btw, here are all links: > > # ls /sys/class/devlink/ > pci:0000:00:00.1--mdio_bus:0000:00:00.1 > platform:5000000.iommu--pci:0000:00:00.0 > platform:5000000.iommu--pci:0000:00:00.1 > platform:5000000.iommu--pci:0000:00:00.2 > platform:5000000.iommu--pci:0000:00:00.3 > platform:5000000.iommu--pci:0000:00:00.5 > platform:5000000.iommu--pci:0000:00:00.6 > platform:5000000.iommu--pci:0001:00:00.0 > platform:5000000.iommu--pci:0002:00:00.0 > platform:5000000.iommu--platform:2140000.mmc > platform:5000000.iommu--platform:2150000.mmc > platform:5000000.iommu--platform:22c0000.dma-controller > platform:5000000.iommu--platform:3100000.usb > platform:5000000.iommu--platform:3110000.usb > platform:5000000.iommu--platform:3200000.sata > platform:5000000.iommu--platform:8000000.crypto > platform:5000000.iommu--platform:8380000.dma-controller > platform:5000000.iommu--platform:f080000.display > platform:f1f0000.clock-controller--platform:f080000.display > regulator:regulator.0--i2c:0-0050 > regulator:regulator.0--i2c:1-0057 > regulator:regulator.0--i2c:2-0050 > regulator:regulator.0--platform:3200000.sata As you can see, most of the links that fw_devlink created are gone. Because all the consumers probed. Any remaining ones you see here are non-SYNC_STATE_ONLY links created by the driver/frameworks or cases where consumers haven't probed. My guess is that only the first one is of this criteria and it doesn't hurt anything here. Try booting with fw_devlink=on and check this list. That'll give you a better idea. -Saravana
